Break-glass station with slide switch protected against false operation



Jan. 21, 1969 H. L. CARETTO -GLASS STATION WITH SLIDE SWITCH PROTECTED v BREAK AGAINST FALSE OPERATION Filed Sept. 29, 1967 FIG.2

FIG.|

UNAE @F INVENTOR.

HOWARD L. CARETTO FIG.3

MXW

ATTORNEY United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE Signal transmitting slide switch with an operating projection restrained by a breakable rod and with exposed parts protected against accidental operation by an outstanding guard wall partially surrounding the same.

Special objects of the present invention have been to provide a safe, simple, low cost form of break-glass signal transmitter having a direct straight line operating movement, protected against accidental or unintentional operation.

These and other desirable objects have been accomplished by a novel combination of parts illustrated by way of example in the drawing accompanying and forming part of this specification.

FIG. 1 is a part sectional front elevation of a fire alarm station form of the invention in the normal ready condition.

FIG. 2 is a side elevation of the same, partly in section as on the line 2-2 in FIG. 1.

FIG. 3 is a broken top plan View of the station.

In these views the invention is shown applied to an open front call box 7, having a cover in the form of a face plate 8, carrying the usual fire alarm operating instructions and having, in its central portion, a vertically extending slot 9.

A slide type of switch is disposed in this slot, incorporating a vertically operating slide member provided with a forwardly or outwardly projecting finger hold 11.

This switch is shown firmly secured thus positioned, substantially closing the slot, by screws 12, passed through lugs 13 at upper and lower ends of the base of the switch, into the supporting face plate.

Connections running from the switch are not shown, but these ordinarily are such as to keep the switch armed, ready to send in a signal, in the upper position of the switch operating slide and to initiate the desired signal in the lowering movement of the slide.

To guard this switch against accidental or unintentional operation, there is provided an outstanding, downwardly faced C-shaped guard wall 14, on the face plate, partially surrounding the slot, with parallel side portions 15 at opposite sides of the slot and an overhead bridging portion 16, over the upper end of the slot.

This guard wall projects beyond the finger piece 11 of the switch slide so as to prevent operation of the switch by an object traversing the face of the call box.

The lower ends of the C-shaped projection are shown as rounded off at 17 to deflect upwardly traveling objects away from the switch control and this guard'wall is made heavy enough, as by being an integral portion of the face plate, which ordinarily may be a casting, to resist blows of a heavy object that might be directed at such a signal box.

The break-glass control is provided in the illustration by a rod 18 of glass or other suitable frangible material, seated in sockets 19, 20, in the opposite side portions 15 of the guard wall and extending in readily breakable relation between these wall portions, immediately below the projecting switch control.

ice

One socket 19 is shown as of closed end formation and the other 20 as open ended so that broken rods may be readily removed and replaced after removal of the closure screw 21, entered in the outer end of the through opening 20.

The slide switch may be of small size and the location of it in the slot in the face plate keeps the overall dimensions down so that the box is kept down to a moderate size.

The downwardly faced C-shaped guard, While not obstructing or delaying considered legitimate operation of the switch, does, in effect, put a protective hood over the switch and restraining element, but open at the bottom for quick, free proper signal transmitting operation of the switch. This intended operation is a straight downward movement readily effected without hindrance from the partially surrounding protective wall.

The C-shaped guard wall, with the breakable restraining rod closing the open side of the same, form an enclosure over and about the switch mechanism preventing tampering with that mechanism.

The switch shown is of the spring loaded type, mounted with the operating slide of the same spring biased in the downward direction of signal switching movement and restrained in the upper, non-signaling position by the breakable rod, so that upon fracture of this rod by any means, the switch will automatically initiate signal.

What is claimed is:

1. A break-glass station comprising the combination of an open front signal box,

a removable face plate closing the front of the box,

said face plate having a vertically extending slot in the central portion of the same, and an outwardly projecting guard wall extending in downwardly facing C-shaped form along both sides and across the top of said slot,

a slide switch mounted on the slotted portion of said face plate and having a forwardly projecting operating finger hold projecting into the space defined by said reversed C-shaped guard wall, and

a breakable rod of frangible material extending across said slot, between said portions of the guard wall at opposite sides of the slot therein and beneath said forwardly projecting finger hold of the slide switch.

2. The invention according to claim 1 with said slide switch disposed within said slot and having a base extended over the surface of the face plate and screw means extending through the extended portions of said base into said face plate.

3. The invention according to claim 1 with said slide switch having a base portion extended over the surface of said face plate and screw means connecting said base portion to said face plate.

4. The invention according to claim 1 in which said slide switch is spring loaded in the downwardly directed movement of the switch slide and normally restrained by said breakable rod so that on fracture of said rod said switch will automatically effect the desired signaling operation.

References Cited UNITED STATES PATENTS 2,726,381 12/1955 Verkuil 200--61.08 2,822,451 2/1958 Holmes 2006l.08

ROBERT K. SCHAEFER, Primary Examiner.

H. O. I ONES, Assistant Examiner.

U.S. Cl. X.R. 

